Pi Day, not to be confused with Pie Day held in January, is a day with deals on pizza, pastry and pot pies.

Aside from calculating your savings, it's a day to have fun with math too, said Syracuse University mathematics professor Graham Leuschke. He said you can search for your birthday in the digits of π and can create a "pi-ku" similar to a haiku poem.

PiDay.org, which calls itself the official site for Pi Day, has additional ideas for activities to celebrate the day.

Pi Day pizza deals

Here are the deals available at participating locations Thursday unless otherwise noted. To be on the safe side, always check with your closest location before heading out. Also, some will require you to have a restaurant's app or be signed up for emails.

Babbo Italian Eatery: The locally-owned Italian restaurant chain with eight locations in metro Phoenix will offer 8” cheese pizzas for $5 all day. Limit is four per person and the deal is available for dine in or take out. Babbo restaurants are located in Glendale, Queen Creek, Cave Creek, Scottsdale, Mesa, Surprise, Phoenix and Tempe.

Cicis: Buy one adult buffet and large drink Thursday and get a second adult buffet for $3.14 with a coupon.

Domino’s: Not specific for Pi Day but through April 28, Domino’s is giving Piece of the Pie Rewards members an easy way to earn points that can redeemed for a free Domino's pizza – no matter what brand's pizza they buy. The latest version of Domino’s mobile app is needed to "to scan a pizza or an eligible image of a pizza.” Learn more at www.pointsforpies.com.

Giordano’s:Giordano’s restaurants in Paradise Valley and Peoria are offering $3.14 off every large pizza order. A large deep dish pizza is 10 slices and feeds 4-6 people. A large thin crust pizza is a whopping 24 slices and feeds 4 people.

Hungry Howie's: Through Thursday, with the purchase of any Howie Bread at regular menu price, get a medium one-topping pizza for $3.14 with promo code 19PI. Carry out orders only. Florida locations are not participating in this promotion.

Pieology: Buy one Artisan Thin Pizza, get a second for $3.14 Thursday. Plus, Pie Life Rewards members making a purchase on Pi Day will get $2 off their next order. The chain also is holding the "Perfect Pieology Pull” cheese-pull contest. “Customers simply visit the nearest Pieology, roll up their sleeves, start pulling, and documenting their best efforts," the company said in a statement. "After submitting their photo or video posts on Instagram using the hashtag, #perfectpieologypull, the public will vote on the top five entries and the best ‘pull’ will be named champion and receive a $50 Pieology gift card.” Enter by midnight Thursday.

Sauce Pizza and Wine: Cheese pizzas are $3.14 if guests mention “Pi Day” when ordering. This offer is available at all Sauce locations, for dine-in only and limited to one per guest per visit.

Cheddar’s Scratch Kitchen: Order the restaurant’s Homemade Chicken Pot Pie for dining in or to-go Thursday and get a free second pie to bake at home. No coupon needed, and Cheddar’s says it will provide the baking instructions. Learn more at www.cheddars.com/pieday.

Kroger: Select pies are $3.14 for Pi Day including apple, cherry, peach and pumpkin pies.

Marie Callender's: Get a free slice of pie Thursday with purchase of a full-price adult menu and a coupon posted at www.mariecallenders.com/coupon-piday. Not valid with other promotions including Kids Eat Free, happy hour menu, lunch combos and daily dish specials.

Schlotzsky’s: The fast-casual chain is celebrating National Potato Chip Day Thursday. Get a free bag of potato chips with entrée purchase.

Starbucks: The coffee giant has one of its Happy Hour events on Pi Day. Starting at 3 p.m. Thursday, buy any grande or larger handcrafted espresso beverage or Frappuccino blended drink and get one free. This deal has been loaded on Starbucks Rewards members accounts. Non-members can sign up for the offer by creating an account at Starbucks.com. You can either add a Starbucks gift card to the account or choose an instant digital card when setting up the account.

Sweet Provisions:Enjoy a slice of any of Sweet Provisions pies for just $3.14 all day long.